stromal micropapillary pattern predominant lung adenocarcinoma - a report of two cases基质micropapillary模式主要肺腺癌,2例报告.pdf

Ohe et al. Diagnostic Pathology 2011, 6:92 /content/6/1/92 CASE REPORT Open Access Stromal micropapillary pattern predominant lung adenocarcinoma - a report of two cases 1,2,4* 1 3 1 1 1 Miki Ohe , Tomoyuki Yokose , Yuji Sakuma , Sachie Osanai , Chikako Hasegawa , Kota Washimi , 2 2 2 2 1 2 Kimitoshi Nawa , Tetsukan Woo , Rurika Hamanaka , Haruhiko Nakayama , Yoichi Kameda , Kouzo Yamada and Takeshi Isobe4 Abstract Generally, adenocarcinomas with micropapillary pattern, featuring small papillary tufts lacking a central fibrovascular core, are thought to have poor prognosis. This pattern has been described in various organs. However, tumor cells with micropapillary pattern of lung adenocarcinoma are more often seen to float within alveolar spaces (aerogenous micropapillary pattern, AMP) than in fibrotic stroma like other organs (stromal micropapillary pattern, SMP) and SMP predominant lung adenocarcinoma (SMPPLA) has not been well described yet. We presented two cases of SMPPLA which were found in the last four years. Both the cases showed more than 50% of SMP in the tumor area. The majority of the stromal micropapillary clusters expressed MUC1 and epithelial membrane antigen along the outer surface of cell membrane. On the other hand, connective tissues surrounding stromal micropapillary clusters showed no reactivity for epithelial markers (thyroid transcription factor-1 and cytokeratin) or endothelial marker (D2-40 and CD34). It means clusters of SMP do not exist within air space or lymphatic or vessel lumens. The tumors with SMP often presented lymp